Method for improving flavor constituents



Dec. 14, 1965 E. J. KELLY METHOD FOR IMPROVING FLAVOR CONSTITUENTS 2Sheets-Sheet 1 Filed D80. 5, 1960 INVENTOR. 5269B (I. KELLY I q!flrrae/vsys.

Dec. 14, 1965 E. J. KELLY 3,223,533

METHOD FOR IMPROVING FLAVOR CONSTITUENTS Filed Dec. 5, 1960 2Sheets-Sheet 2 IN V EN TOR. 5269a r]: E51. L y

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United States Patent 3,223,533 METHOD FOR IMPROVING FLAVOR CONSTITUENTSEdgar J. Kelly, Placentia, Calif., assignor to Libby, McNeil] & Libby,Chicago, Ill., a corporation of Maine Filed Dec. 5, 1960, Ser. No.73,742 16 Claims. (Cl. 99-140) The present invention is directed to amethod of separating the characteristic odor and flavor constituentsfrom aqueous source materials generally derived from fruit, berries,beverage materials, such as tea and coffee, etc. The invention is alsodirected to specific conditions and arrangements of elements for theproduction of a new concentrate or distillate containing the flavor andaroma constituents in very large proportion or high concentration. Thepresent invention is also directed to both a method and apparatus forremoving traces of oily constituents which contaminate the flavor andaroma constituents. This application is a continuation-in-part ofapplication Serial No. 766,902 filed October 13, 1958, now Patent No.2,992,978, entitled Method and Apparatus for Producing FlavorConstituents.

For many years it has been recognized that fresh fruit and vegetablejuice contained flavoring and aromatic constituents which are extremelycharacteristic of the particular fruit, plant extract or the like. Ithas also been recognized that the natural, fresh flavor and aroma offruit, berries, tea, coffee and other foods are deleteriously affectedby the normal concentrating, heating and sterilizing steps, with cookedand off flavors and with a loss of the aroma and flavor whichcharacterizes fresh, mature fruit. Some attempts have been made in thepast to recover the relatively volatile flavors and components found inplant products for the purpose of reintroducing them into the finalconcentrate or canned, cooked or sterilized fruit in order to impartthereto the flavor and aroma of the fresh, natural fruit.

Prior attempts to obtain a fraction in which it was hoped that theflavoring and aromatic constituents would be present in concentratedquantity were not successful and were fallacious in their method ofoperation. Prior workers in this art appeared to be confused and lookedfor an oily material as a source of the flavor. The present inventionobtains the flavoring and aromatic constituents in a non-oily,water-soluble and miscible form which is virtually colorless,transparent, mobile, burns with a clear blue flame and has a remarkablylow freezing point, well below 100 C. and as low as 180 C.

In addition directly contrary to the teaching of the prior art, it hasbeen found that oily contaminants are present with the flavor andaromatic constituents in certain citrus products, which even inextremely small proportions impart unpleasant taste and odorcharacteristics. Also it has been found that the flavor concentrateitself is a solvent for such oily contaminates so that if the oilycontaminants are not removed prior to concentration of the flavor andodor constituents then separation becomes extremely difflcult if notimpossible.

One of the reasons for the failures of the prior art was the fact thatthe prior workers did not realize the importance of maintainingconditions of temperature and pressure below 65 C. and 190 mm. of Hgwhen dealing with fruit juices, citrus juices and other sourcematerials. It has been found that the conditions of operation should besuch as to prevent or minimize hydrolysis of the esters and ethers ofacetic acid into acids, alcohols and secondary reaction products. It hasalso been discovered that the esters and ethers of acetic acidconstitute important components which impart the characteristic fresh,natural flavor and aroma elements to the concentrate and to the productsin which it is subsequently used; colorimetric determination of theethyl ester of acetic acid (ethyl acetate) content of a concentrateprovides a ready mode of evaluation.

Although some prior patentees have referred to what they termed a foldessence which they allegedly obtained, such term had no true meaningother than the volume of the condensate taken out of the system was 5 ofthe juice fed into the system. For example, Patent No. 2,457,315 speaksof pumping 50 g.p.h. of apple juice into a single stage evaporator,evaporating 10% of such juice, passing the vapors into a fractionatingcolumn and condensing the vapors from such column, all at atmosphericpressure. Uncondensed gases were vented from the condenser and thecondensate was drawn off at of the rate at which fresh juice was fedinto the evaporator, this condensate being termed a 100 fold essence. Itis evident that in such process the condenser would be fed with vaporscomposed essentially of water and therefore the condensate would alsoconsist essentially of water since the water will be condensed first.The mole fraction or concentration of the flavor constituents in vaporssent to such prior condenser is far below 0.5% and the vapors wouldexhibit all of the properties of water vapor. The partial pressure ofthe volatile constituents at no time approach saturation pressures. Atno time would the prior patentees eliminate the water and then condensethe more volatile constituents under conditions which effectivelyutilized partial pressure phenomena and Daltons law. Dew pointconditions (with respect to the flavoring and aromatic constituents)were never reached; the mixtures of air, gases and vapors sent to thecondenser contained excessive amounts of Water vapor. As a result, theso-called 100 fold essence was simply a mathematical and volumetricdetermination and did not actually contain any appreciably increasedquantity of flavoring components.

The fallacy of the prior method of identifying the essence becomesapparent when one considers that orange juice appears to contain onlyabout 30 p.p.rn. of true essence, so that only about 1.5 to 1.6 lbs. ofwaterfree essence can be obtained from 52,000 lbs. of citrus juice. Theproducts made by the method of this invention actually contain onethousand times as much flavoring constituents as the original sourcematerial or juice, even in the unpurified, aqueous solution form inwhich they are normally obtained. Moreover, it is to be remembered thatethyl acetate has a vapor pressure of 760 mm. absolute at about 77 0.,whereas water at the same temperature has a vapor pressure of 7 lbs.gauge.

Contrary to prior suggestions that the concentrated or flavor-strippedjuice be used as an absorbent or scrubber for the non-condensed gases orvapors prior to venting such residual gases (in an attempt to recoversome of the flavoring components from said gases), it has been foundthat such flavor-stripped juices are not good absorbents; instead, purewater (or dilute, aqueous solutions of ethyl alcohols or sucrose) havebeen found much more effective. Also contrary to prior practice whichwas concerned solely with removing water in order to obtain a smallvolume of liquid to be fractionally distilled, the present inventionafter initially obtaining a small volume liquid actually adds water toseparate the oily contaminants prior to fractional distillation sincesimple condensation does not separate the oily contaminants from theflavor constituents.

Generally stated, therefore, the present invention departs from theprior art and relates to a method of obtaining flavoring constituentsfrom aqueous source materials (such as juice of fresh, natural,deciduous and citrus fruits, berries, aqueous extracts of tea leaves,roasted and ground coffee, etc.) by conducting all of the operationsunder temperature and pressure conditions which will not causehydrolysis of esters of acetic acid, the temperatures not exceeding 65C. and preferably being below 43 C. and absolute pressures not over 190mm. of Hg and preferably as low as 30 mm. Hg. Any such source materialin the form of water vapor and non-condensable gases containing minutequantities of volatile ordor and flavor constituents is subjected to atemperature below about 43 C. and an absolute pressure of not over 115mm. Hg in a condensation zone to condense not less than 70%, andpreferably 80% by weight of water contained in said source material.After the water has been separated from the residual vapors and gases,such vapors and gases are subjected to dew point conditions for flavorand odor constituents and are readily condensed in accordance withDaltons law. These flavor and odor constituents are obtained in the formof aqueous solutions having the characteristics described hereinbeforecontaining in excess of 40 grams per liter of such constituents.Ordinarily, the final product contains 30,000 to 60,000 p.p.m. of thevolatile flavor-and aroma-imparting constituents, this being a readilyhandled and utilized product which is not as unstable as the pureessence; more concentrated forms have to be handled at very lowtemperatures because of their volatile character.

When the source material in the form of a gaseous mixture of water vaporand odor and flavor constituents contains traces of oily contaminants,it is first scrubbed with chilled water. Then it is cooled and scrubbedagain with chilled water. The oily contaminants are then removed fromthe scrub water. The water and scrubbed gaseous mixture are thenfractionally distilled to produce the gaseous mixture from which theflavor and odor constituents may be fractionally condensed.

It is an object of the present invention, therefore, to disclose andprovide means, methods and conditions whereby concentrated distillatesor products containing flavorand aroma-imparting constituents may bederived from various aqueous media.

A further object of the present invention is to provide means, methodsand conditions whereby oil-free flavor and odor constituents may beseparated from a gaseous mixture contaminated with oily constituents.

A further object is to disclose and provide a novel concentrated productcontaining flavorand aroma-imparting constituents at a concentration inexcess of about 30,000 p.p.m. for use in various foods and foodproducts.

Those skilled in the art will readily appreciate various other objectsand advantages devised by the use of the modes of operation andconditions hereinafter disclosed in greater detail in connection withthe description of an exemplary arrangement of apparatus in which theprocess may be carried out in the treatment of citrus juices. Theappended diagrammatic representation of an arrangement of equipment,FIGS. 1 and 2, is directed to the recovery of an essence composedlargely of odor and flavor constituents of the character describedhereinbefore. FIG. 3 is a diagrammatic representation of an arrangementof equipment for the recovery of flavor and odor constituentscontaminated by traces of oily constituents.

In the exemplary form of apparatus shown in the appending diagram FIG.1, fresh citrus juice may be introduced into the first of a pair ofmultiple efi'ect evaporators 1 and 1? and a concentrated juice (fromwhich 15% to about 20% of original water has been removed) is dischargedfrom the second evaporator. Water vapors from the second evaporator maybe sent by line 2 to condenser 2 and its condensate is normally sent towaste. Noncondensable gases from 1 are sent to 1' by line 1";noncondensable gases from 1 and condenser 2 are sent by lines 3 and 3'to a fractionating column 6. Since the condensate from 1 contains someflavor and aroma constituent (this may also be true to a lesser degreeas to condensate from 2), the condensate is pumped as by pump 5 and fedby line 4 to column 6. Those skilled in the art will understand thatsuitable supply of heat, valves, temperature and pressure indicatingdevices etc. are used and need not be shown in the diagram.

It is highly desirable that the multiple ettect evaporators be operatedat as low temperature as possible, preferably below 65 0, althoughsomewhat higher temperatures may be employed. It is to be understoodthat the arrangement of evaporators or other equipment from which thenon-condensable gases and extracts or solutions are obtained are not anessential part of this invention; these preliminary units and operationswill vary in accordance with the material being treated; if, forexample, a coffee essence is to be obtained, no evaporators would beused, but instead, leaching tanks would be employed for the purpose ofobtaining an aqueous extract of cotfee, such extract being made at a lowtemperature of below about 65 C. and preferably at a temperature ofbelow about 43 C.

The equipment illustrated in the diagram FIG. 1 and adapted to carry outthe process herein disclosed comprises, in addition to the fractionatingcolumn 6, a primary overhead type of condenser indicated at 12, a seriesof saturation component condensers indicated at 18 and 20, a scrubberindicated at 26 and a constant pressure chamber indicated at 30. It isto be understood that additional saturation component condensers may beemployed, the diagram being limited to the two, 18 and 20, only forpurposes of simplification. The entire system from the fractionatingcolumn 6 to the constant pressure chamber 30 is maintained under asubstantially uniform vacuum. Uniform and constant vacuum conditionsbelow about mm. Hg are preferably maintained throughout the system andthe series of condensing steps are performed at progressively lowertemperatures ranging, for example, from 22 C. to 1 C., the lastcondensing step, for example, being at a temperature between 1 C. to 10C.; it has been found desirable to maintain pressures as low as 30 mm.Hg in the saturation component condensers 18 and 20 and the scrubber 26.The desired vacuum conditions are attained by connecting the outlet line31 extending from the constant pressure chamber 30 to a suitable sourceof vacuum, such as a barometric condenser, suitable pumps, ejectors orthe like.

The fractionating column 6 is maintained with a bottom temperature ofnot over about 55 C., although temperatures as high as 65 C. may be usedin some instances. Temperatures at the top of the fractionating columnshould not exceed 43 C. and are preferably maintained on the order ofabout 32 C.33 C. A part of the bottoms discharged from the bottom of thefractionating column 6 as by line 7 and sent to the pump 8 may berecirculated through a reboiler 9 and returned to the fractionatingcolumn, as indicated. These bottoms may be discharged by the pump 8 towaste or other disposal.

The vapors from the fractionating column 6 are discharged by line 10 tothe condenser 12. The temperature and pressure conditions Within thecondenser 12 are such as to condense not less than about 70% by weightof water contained in the vapors submitted to such condenser through theline 10. As previously indicated, the virtually constant subatmosphericpressure is maintained throughout the system and such pressure should bebelow about mm. Hg. In actual practice, pressures of approximately 50mm. Hg to as low a 30 mm. Hg are employed; under such pressureconditions the temperature within the condenser 12 is maintained atbetween about 30 C. and 43 C. in order to thoroughly strip the gases ofat least 70% of their moisture content.

The condensed water is discharged from the overhead condenser 12 as byline 13 and the uncondensable components, residual vapors and gases, aredischarged as by lines 14 and 14 into the first of a series ofsaturation component condensers such as the condensor 18. A

valve is indicated in the line 14 and although normally kept open, maybe used to slightly throttle the gases and assure condensation of therequired amount of water in the condenser 12.

The condenser 18 is operated at a temperature of, say around 16 C.-18C., and gases which have not been condensed in the condenser 18 aredischarged by line 19 into the condenser 20, which in the example beinggiven, would now operate at a still lower temperature, say, atemperature of approximately 10 C. The odor and flavor constituentswhich have been condensed in condensers 18 and 20 are dischargedtherefrom by lines 18' and 20, respectively, into a manifold line 21,permitting these odor and flavor constituents to be combined. Theuncondensed vapors and gases from condenser 20 are then shown being sentby line 22 to the scrubber 26. This scrubber also operates at the verylow pressure of 30 mm. to 50 mm. Hg and spray of scrubbing liquidsupplied thereto by line 23 is preferably chilled as by a chiller 24before introduced into the scrubber. As previously indicated, it isdesirable to use clean, pure water as a scrubbing liquid and such watermay be supplied to the chiller 24 by means of pump 25 and line 23. Theliquid from the scrubber 26, containing its absorbed and adsorbed odorand flavor constituents, is discharged into the line 21. The stilluncondensed and uncondensable vapors or gases from the scrubber are nowdischarged as by line 27 into the constant pressure chamber 30. FIG. 2represent an enlargement of constant pressure chamber 30 and shows moredetails of its construction. This device insures constancy of vacuumthroughout the system and contains a body of water in it lower portion,together with a temperature control device indicated at 32 whichactuates a valve (or switch) so as to admit either steam or electriccurrent into a heating coil located in such body of water in the eventthe temperature of the body of water drops below a predetermined point.A float control is also provided (indicated at 33) for the purpose ofmaintaining a constant level of water in the device. As previouslyindicated, the outlet pipe 31 leading from the constant pressure chamberis associated with a suitable source of vacuum.

The condensates discharged from condensers 18 and 20 and the scrubber 26will contain the greatest concentrations of the odor and flavorconstituents. For example, when the system is operated on orange juice,the concentrations obtained will range from between about 10,000 ppm. to150,000 ppm. The condensate from the primary condenser 12 will alsocontain some odor and flavor constituents but at a low concentration,say, only 100 to 200 ppm. Although the condensates and concentrates fromthe condensers 18 and 20 and scrubber 25 may be combined in a line 21and separately withdrawn as indicated by line 28 through a pump 29 andsent to essence tanks, bottling, or the like, it has been founddesirable to combine these concentrates with the condensate from theprimary condenser 12 because of the relatively large amount of thecondensate obtained from condenser 12 in comparison with the relativelysmall quantities (having high concentration of odor and flavorcomponents) obtained from the condensers 18, 20, etc. FIG. 1 thereforeshows line 21 in communication with outlet line 13, all of theconcentrates being sent through a pump 16 and then by line 17 tostorage.

In the specific embodiment of apparatus shown in FIG. 3, the arrangementof evaporators is the same as that used in FIG. 1. However thenon-condensable gases from evaporator 1' and condenser 2 are sent bylines 3 and 3' to a scrubber 40 rather than directly to fractionatingcolumn 6. Likewise the condensate from evaporator 1' and condenser 2 ispumped by pump 5 and line 4 to a centrifuge 62 rather than directly tofractionating column 6. Accordingly, the non-condensable gases and thecondensate are processed before entering the fractionating column 6 andafter entering the fractionating column 6 will exit through line 10 tobe further processed in the same manner as the vapors passing throughline 10 shown in FIG. 1. The gaseous mixture entering srubher 40 usuallycontains about 0.01% oily contaminants and 60% water vapor but maycontain over 0.1% oily contaminants. Since the operating pressure ofscrubber 40 is preferably maintained at about 10 mm. Hg, Daltons lawindicates that the partial pressure of the oily contaminants is usuallyabout 0.001 mm. Hg assuming a concentration of 0.01%. At such extremelylow partial pressures, it can be seen that extremely low temperatureswould have to be attained in order to simply condense the oilycontaminants. This point is emphasized by the fact that the oilycontaminants appear to be somewhat more volatile than water and thusmore difl'icult to condense. Hence scrubber 40 while it does remove asmall part of the oily contaminants serves primarily to increase theirconcentration by removing other components of the gaseous mixture. Bycharging chilled water at about 35 F. at 41 and removing it at 40, alarge portion of the water vapor and other gaseous components areremoved so that the gaseous mixture leaving scrubber 40 through conduit42 usually con tains about 1% oily contaminants and 10% water vapor.

The gaseous mixture i pumped through scrubber 40 and conduit 42 by meansof a steam jet pump 43 which is fed super-heated steam by steam line 44.During the pumping operation of the pump 43 the super-heated steam willbe mixed with the gaseous mixture. The steam jet pump is used to avoidfurther contamination of the ga mixture with oil. Also by placing thesteam jet pump after scrubber 40, the amount of gas to be pumped isminimized and consequently the amount of water added to the gas mixturein the form of steam is minimized. However, the gaseous mixture leavingthe steam jet pump 43 through conduit 43 at about 40 C. and 30 mm.50 mm.Hg has oily contaminants in substantially reduced concentration andgreatly increased water vapor concentration i.e. it usually hasapproximately 0.1% oily contaminants and water vapor. Therefore thegaseous mixture is sent through condenser 45 where a large portion ofthe water vapor is condensed and removed along with other condensablecomponents of the gaseous mixture through conduit 45. The gaseousmixture leaving condenser 45 through conduit 46 consequently usuallycontains about 5% oily contaminants and 15% water vapor.

The gaseous mixture is then sent through a scrubbercondenser 47 where itis cooled to about 35 F. by a coolant such as ammonia and scrubbed withWater. Because of the relatively high concentration of oily contaminantsin the scrubber-condenser 47 e.g. usually about 5% and the absorbingeffect of the scrub water, the water leaving scrubber-condenser 47through conduit 47 usually contains about 5% oily contaminants. Suchresult can be understood since the operating pressure of the scrubbercondenser is usually about 30 to 50 mm. Hg so the partial pressure ofthe oily contaminants is at least about 1.5 mm. Hg and hence their dewpoint can be attained. The gaseous mixture is then sent by conduit 48from scrubber-condenser 47 to scrubber 49 for a final scrub with chilledwater at about 35 F. entering at 50. The scrub water leaves scrubber 49through conduit 48 to be reused in scrubber-condenser 47. The gaseousmixture leaving scrubber 49 through conduit 51 to feed fractionatingcolumn 6 contains no ascertainable oily contaminants but still containsthe major portion of the flavor and odor constituents since they arepresent in such small concentrations throughout the steps for removingthe oily contaminants.

The scrub water from scrubber-condenser 47 is combined with thecondensate from condenser 45 and the scrub water from scrubber 40 inconduit 61 and sent through cooler 60 to reduce resulting combinedliquid temperature to about 35 F. The combined liquid stream leavingcooler 60 contains only about 0.5% oily contaminants so the lowertemperature is preferred to facilitate separation. The liquid leavingcooler 60 through conduit 60' is combined with condensate fromevaporator 1 and condenser 2 and sent to a centrifuge 62 where about99.9% of the oily contaminants are removed through conduit 63. Thesubstantially oil-free aqueous solution leaving centrifuge 62 throughconduit 64 is pumped by pump 65 through conduit 66 to a filter 67 wherethe last traces of oily contaminants are removed. Pump 65 must not beoil-lubricated since this would add additional oily contaminants. Onetype of pump which may be used is a centrifugal pump with a mechanicalseal. Filter 67 may be a conventional filter with a filter aid such asdiatomaceous earth so long as the effective filter openings aresufficiently smaller than the oil globules in the aqueous solution e.g.filter openings of approximately 1 micron compared to oil globules ofapproximately 10-100 microns. The aqueous solution leaving filter 67 byconduit 68 is then heated by heater 69 and sent to fractionating column6 through conduit 70.

The following data may be of interest in indicating the results obtainedon orange juice where the fractionating tower 6 was fed with vapors andconcentrate containing approximately 30 p.p.m. of the odor and flavorconstituents and the entire system was maintained at a subatmosphericpressure of 45 mm. Hg. The concentrate from the condenser 12 maintainedat a temperature of 38 C. contained about 100 p.p.m. of the essence andamounted to two gallons per minute; the condensate from condenser 18(maintained at a temperature of 16 C.) contained 20,000 p.p.m. of theessence but the discharge amounted to only 0.1 g.p.m.; the condensatefrom condenser 20 (maintained at a temperature of 10 C.) contained100,000 p.p.m. of essence discharged at the rate of 0.1 g.p.m.; thescrubber 26, maintained at a temperature of only 2 C., accounted for 0.5g.p.m. containing about 10,000 p.p.m. of essence.

As previously indicated, the temperature and pressure conditions withinthe entire system and throughout the process are such as to prevent orminimize hydrolysis of the esters and ethers of acetic acid into acids,alcohols and secondary reaction products. A determination of the ethylacetate content of the concentrate or condensates is the simplest andmost effective method of determining the actual presence of the odor andflavor constituents and in evaluating such concentrates and essence. Forpurposes of the record, the following reagents and methods are employedin making the ethyl acetate determinations:

Reagents employed (percent designations are weight/ volume)Determination Transfer 200 ml. of juice to an 800 ml. Kjeldahl flask,add 5 drops of mineral oil, a few glass beads and distill 50 ml. into 40ml. of water in a 125 ml. Erlenmeyer flask. The distillate is deliveredbelow the surface of the receiving water by means of a glass tubeconstricted to a 2-3 mm. orifice. The receiving water is kept chilled bymeans of an ice water bath to minimize escape of the esters. Dilute thedistillate to ml.

Pipette 2 ml. of hydroxylamine reagent into a 50 ml. Erlenmeyer flaskand add 5.0 ml. of the ester sample (standard solutions or distillates)followed immediately with 2 ml. of the sodium hydroxide reagent.

The hydroxylamine may be added to all flasks of a given assay at onetime but the sodium hydroxide must be added as soon as possible aftereach ester sample. Mix and allow to stand for five minutes and then add2 ml. of the hydrochloric acid reagent and mix. The individual flasksmay be held at this point until all samples and standards of a givenassay are also at this stage. Add 2 ml. of the ferric chloride reagent,mix, pour 5 ml. into a Klett tube, and read immediately, using filter 54in a Klett photoelectric colorimeter which has been set at zero using ablank of 5 ml. of water plus 2 ml. of each of the four reagents.

Rinse Klett tube with a few ml. of colored sample before filling withthe next sample. Use the same tube for all color readings. If matchedtubes are available, the color may be developed directly in the tubeusing onehalf as much of sample and reagents. Mix with a flattippedglass rod.

Calculate esters as ethyl acetate by comparison with the standards.

The above reagents and method of determination are particularly welladapted for the determination of the odor and flavor constituents inrelatively dilute or low concentrations. The content of ethyl acetate inthe essence or concentrates is normally obtained by diluting theconcentrates to a desirable point, say, within a range of colorimetricdetermination against samples having a standard of 1000 or 5000 p.p.m.

The essence obtained from the juice of citrus fruits, crushed berriesand grapes, purees of deciduous fruits (such as apricots, apples, pears,peaches, etc.) can be used to impart a natural, fresh and characteristicflavor and aroma to food products and confections, ice cream, etc. orreincorporated into the concentrated source material. Orange essenceobtained by this process can be added to concentrated orange juice andconvert the usual fiat, cooked taste of reconstituted beverages madefrom such concentrates into beverages which cannot be distinguished fromnatural fresh juice. Citrus essences obtained by the methods hereindisclosed are free from the terpene-like odors and flavors whichcharacterize citrus oils. One of the important characteristics of theessences recovered by this process is stability upon storage; this maybe due, in part at least, to the fact that hydrolysis and decompositionare minimized at the low temperature and pressure conditions, and to thefact that all of the constituents (including naturally containedstabilizing agents) are present in their usual, natural proportions.

Emphasis is again placed upon the necessity of maintaining low, uniformsubatmospheric pressures throughout the system composed of thefractionating tower and condensers and the conjoint use of progressivelylower temperatures at such uniform subatmospheric pressure in the seriesof condensation zones, for example at a pressure below about 120 mm. Hgand at progressively lower temperatures between 21 C. and 2 C. or at apressure of below about mm. Hg and at progressively lower temperaturesbetween 22 C. and 2 C., in order to obtain an essence containing theexceptionally high content of odorand flavor-imparting constituents in aform unaltered from that assumed by the constituents in the fresh,natural source material. For best results the maximum temperature ofvapors should be below about 55 C. at a pressure of not above 115 mm. Hgabsolute. Piping between condensers, scrubbers and fractionating towershould be sufliciently large to avoid any material varia tion inpressure in the system. The constant pressure device 30 performs theimportant function of preventing the pressure in the condensers fromdropping. For example, when the temperature of the vapors in the top offractionating column 6 is to be maintained at 38 C., the body of waterin 30 is also maintained at 38 C. by control device 32 and the watervapor generated at 30 prevents the barometric condenser, ejector, purgeor vacuum pump from dropping the pressure in 12, 18, 20 and 26 below thedesired pressure of, say, 50 mm. Hg. It is to be noted that 1 lb. of aircan carry about lbs. of water vapor at 38 C. and 50 mm. Hg, but willcarry about 24 lbs. of water vapor at the same temperature if thepressure drops to 48 mm. Hg; 1 lb. of air can carry about 4 lbs. ofwater vapor at 38 C. and 56 mm. Hg. These figures show the necessity ofmaintaining a uniform pressure, condensing and removing the majorproportion of water from the gases and then decreasing the temperatureto obtain the benefit of the change in partial pressures and reach thedew point of the flavor and odor constituents. Although 1 lb. of airwill carry 10 lbs. of water vapor at 50 mm. Hg and a temperature of 38C., only 0.2 lb. of water vapor can be carried by 1 lb. of air at 50 mm.Hg and a temperature of 16 C.; at 10 C. and the same pressure, the watervapor capacity of air is down to about 0.14 lb. Applicant thereforeutilizes a mode of operation which distinguishes from all prior methods,and is able to obtain condensed essence containing in excess of 30,000p.p.m. of the desired constituents in commercial installations.

It must also be emphasized that when oily contaminants are present inthe gaseous mixture even in extremely low concentrations, they must beremoved. Prior practice failed to remove such oily contaminants not onlybecause the result they produced i.e. off-flavored concentrate was notrecognized but also their high volatility and low concentrationprevented their removal by simple condensation or scrubbing. The presentinvention by first increasing the concentration of the oily contaminantsin the gaseous mixture containing the odor and flavor constituents andthen scrubbing the gaseous mixture at a low temperature is able toremove the oily contaminants. The actual equipment necessary to obtainthis result can vary considerably from that schematically illustrated.For example, the steam jet pump with its associated condenser isunnecessary where a suificient vacuum can be maintained by the vacuumpump connected to the outlet line 31 such as when a barometric condenseris used with a relatively high operating temperature. Also the finalscrubber is unnecessary where the scrubber-condenser is sulficientlylarge and the scrubber-condenser itself may be replaced by two pieces ofequipment i.e. a scrubber and a condenser. However the combination ismore economical and efficient. Of course, if the temperature of thegaseous mixture leaving the first scrubber is sufficient low e.g.approximately 35 F. because of entering at a low temperature and thegaseous mixture goes directly to a second scrubber then condenserbecomes unnecessary since its function has already been performed byusing the low entering temperature.

The essence of coffee, tea, cacao beans, and other condiments and foodproducts can be obtained by leaching the ground source materials withwater at a temperature below about 30 C.-35 C. and then supplying suchaqueous infusions to the fractionating tower and its associated systemof condensers under the conditions hereinbefore described. Even in thecase of coffee, the resulting essence is a colorless, clear,water-miscible, mobile and volatile liquid of extremely low freezingpoint; a room is filled with the aromatic and stimulating fragrance offreshly percolating coffee when the stopper is removed from a smallbottle of such essence. Alkaloids are absent and such coffee essence maybe used in making flavorful cofiee by addition to any innocuous,suitably colored aqueous solution.

The equipment employed in the performance of the methods hereindisclosed can vary greatly from that schematically illustrated.Attention is called to the fact that each of the condensers and chillersis provided with suitable heat exchange devices supplied with coldwater, brine or refrigerant under automatic temperature-responsivecontrols. Those skilled in the art can readily construct the equipmentin the light of this invention for any given volume of vapors andnon-condensable gases per hour, and evaluate the resulting essenceconcentrates by the test method herein disclosed.

I claim:

1. In a method of separating and isolating odor and flavor constituentsof natural fruit and berries from water vapor and non-condensable gasescontaining a minute quantity of said constituents the steps of:separating a source material composed of water vapor and non-condensablegases containing a minute quantity of volatile odor and flavorconstituents at a temperature below about 43 C. and absolute pressure ofnot over mm. Hg in a condensation zone to condense not less than 70% byweight of the water contained in said source material thereby increasingthe partial pressure of the odor and flavor constituents in residualvapors and gases; separating the condensed water from the residualvapors and gases; passing said residual vapors and gases through aseries of condensation zones maintained at virtually equal absolutepressure below about 115 mm. Hg, the temperatures in said zones beingmaintained at progressively lower levels between about 22 C. and 2 C.;and combining the condensates from said series of condensation zones toobtain a virtually colorless liquid containing said odor and flavorconstituents.

2. A method as stated in claim 1, wherein the source of materialcomposed of water vapor and non-condensable gases is derived by lowtemperature evaporation and concentration of orange juice.

3. A method as stated in claim 1, wherein the source of materialcomposed of water vapor and non-condensable gases is derived by lowtemperature, fractional distillation of an aqueous liquid obtained byleaching roasted and crushed coffee berries with Water at a temperaturebelow 30 C.

4. A method of separating the characteristic odor and flavorconstituents of natural fruit and berries in the form of a virtuallycolorless, water-miscible, liquid having a freezing point below 100 C.from aqueous source materials derived from fruit and berries containingsaid constituents, comprising: subjecting aqueous source materials andgaseous derivatives thereof containing said constituents tofractionation at a maximum bottom temperature not exceeding 65 C. and amaximum top temperature not exceeding 43 C. and absolute pressure nothigher than 190 mm. Hg to preclude the hydrolyzation of ethyl acetateand produce large volumes of water vapor and gaseous constituents;subjecting the water vapor and gaseous constituents to a temperaturebelow 43 C. at a subatmospheric pressure sufficient to condense not lessthan 70% of the total water contained in said vapors but above dew pointconditions of the odor and flavor constituents; separating the condensedwater from the gaseous constituents and then subjecting said gaseousconstituents to a series of fractional condensation steps in asuccession of interconnected condensation zones all at a substantiallyuniform subatmospheric pressure of below about mm. Hg and atprogressively lower temperatures between 21 C. and 2 C., and combiningthe fractional condensate so obtained, said combined condensatescontaining odor and flavor constitutents of the original aqueous sourcematerials.

5. A method as stated in claim 4 wherein said series of fractionalcondensation steps are performed in a succession of condensation zonesconnected in said series, the last of said zones being connected to asource of vacuum; and inducing sufficient water vapor into theconnection between said source of vacuum and last zone to maintain avirtually constant vacuum in said zone.

6. A method as stated in claim 4, wherein the aqueous source materialsand gaseous derivatives thereof constitute concentrated orange juice andnon-condensable gases from a concentrator.

7. A method as stated in claim 4, wherein the aqueous source materialconstitutes an aqueous liquid obtained by leaching roasted and crushedcoffee berries with water at a temperature of below 30 C.

8. In a method of recovering volatile flavor and odor impartingconstituents in liquid form from aqueous media containing saidconstituents comprising: vaporizing water vapor and non-condensablegases from said aqueous media at a temperature not above 43 C. and anabsolute pressure of not over 115 mm. Hg; subjecting said vapors to asequence of condensing steps in series at a uniform subatmosphericpressure of below 115 mm. Hg at progressively lower temperatures thanthe temperature in the vaporizing step; applying vacuum of below 115 mm.Hg to the gases discharged from the last of said series of condensingsteps; and introducing suflicient water vapor into the gases dischargedfrom the last of said series of condensing steps to maintain saiduniform subatmospheric pressure during each of said series of condensingsteps.

9. A method as stated in claim 8, wherein not less than about 70% oftotal water vapor is condensed from said water vapor and gases in thefirst condensing step of said series, and the last of said condensingsteps is at a temperature of between 1 C. and C.

10. A method as stated in claim 8, wherein the last of said series ofcondensing steps comprises scrubbing the non-condensable gases with coldWater at a temperature of between 1 C. and 10 C.

11. In a method of recovering volatile flavorand odorimpartingconstituents in liquid form from an aqueous media containing oilycontaminants along with said constituents the steps of; vaporizing Watervapor and noncondensable gases from said aqueous media at a temperaturenot above 43 C. and an absolute pressure of not over 115 mm. Hg;subjecting the gaseous mixture to suc cessive scrubbing steps with addedcold Water to condense the major portion of the water vapors and all ofthe oily contaminants without substantially condensing the flavor andodor constituents; removing the oily contaminants from the addedscrubbing water; combining the residual gaseous mixture with its flavorand odor constituents with the de-oiled added scrubbing water;vaporizing at least a portion of said mixture; subjecting said vapors toa sequence of condensing steps in series at a uniform subatmosphericpressure of below 115 mm. Hg at progressively lower temperatures thanthe temperature in the vaporizing step whereby at least 70% of the totalwater vapor is condensed in the first condensing step of said series;applying vacuum of below 115 mm. Hg to the gaseous discharge from thelast of said series of condensing steps; and introducing sufficientwater vapor into the gases discharged from the last of said series ofcondensing steps to maintain said uniform subatmospheric pressure duringeach of said series of condensing steps.

12. A method of separating the characteristic odor and flavorconstituents of natural fruit and berries in the form of a virtuallycolorless, Water-miscible, non-oily liquid having a freezing point below100 C. from aqueous source materials derived from fruit and berriescontaining oily contaminants and said constituents comprising:vaporizing Water vapor and non-condensable gases to form a gaseousmixture from said aqueous medium at a temperature not above 43 C. and anabsolute pressure of not nover 115 mm. Hg; scrubbing the gaseous mixturewith added cold water to condense the major portion of the water vapors;cooling and scrubbing said gaseous mixture with added cold water tocondense water vapor and all of the oily contaminants withoutsubstantially condensing the flavor and odor constituents; combining theadded scrubbing water with a portion of the aqueous source materialsderived from said fruit and berries to obtain an aqueous mixture andremoving the oily contaminants therefrom; subjecting the residualgaseous mixture with its flavor and odor constituents and said aqueousmixture to vacuum distillation by fractionation at a maximum bottomtemperature not exceeding 65 C. and a maximum top temperature notexceeding 43 C. and at absolute pressure not higher than 190 mm. Hg topreclude the hydrolyzation of ethyl acetate and produce large volumes ofWater vapor and gaseous constituents subjecting the water vapor andgaseous constituents to a temperature below 43 C. at a subatmosphericpressure suflicient to condense not less than 70% of the total watercontained in said vapors but above dew point conditions of the odor andflavor constituents; separating the condensed water from the gaseousconstituents and then subjecting said gaseous constituents to a seriesof fractional condensation steps in a series of interconnectedcondensation zones all at a substantially uniform subatmosphericpressure of below 120 mm. Hg and at progressively lower temperaturesbetween 21 C. and 2 C., and combining the fractional condensates soobtained, said combined condensates containing in excess of 40 grams perliter of a transparent and virtually colorless, non-oily liquid composedof characteristic odor and flavor constituents of the original aqueoussource material.

13. A method for separating oily vapor contaminates from a gaseousmixture containing water vapor and flavor and odor constituents and lessthan 1% of such oily contaminants whereby the deleterious effect of saidoily contaminants on said flavor and odor constituents is avoidedcomprising: subjecting the gaseous mixture to successive scrubbing stepswith added cold Water to condense the major portion of the water vaporsand all of the oily contaminants without substantially condensing theflavor and odor constituents; removing the oily contaminants from saidadded scrubbing Water; and combining the residual gaseous mixture withits flavor and odor constituents with the de-oiled added scrubbingWater.

14. A method as stated in claim 13 wherein said successive scrubbingsteps comprise scrubbing said gaseous mixture with added cold water andthen cooling and scrubbing said gaseous mixture with additional coldwater.

15. A method for pre-treating an aqueous feed material containingvolatile flavor and odor constituents and also less than 0.1% unstableoily components which tend to impair the quality of the flavor and odorconstituents to remove substantially all of such unstable oilycomponents without damage to the flavor and odor constituentscomprising: vaporizing water vapor and non-condensable gases from saidaqueous feed material at a temperature not above 65 C. and an absolutepressure of not over mm. Hg; condensing a major portion of the watervapor from said gaseous mixture; scrubbing said gaseous mixture withadded cold water; pumping and mixing said gaseous mixture withsuper-heated steam; condensing a major portion of water vapor from saidgaseous mixture; cooling and scrubbing said gaseous mixture with addedcold water; combining the liquid condensate and added scrubbing Waterand removing the oily contaminants from said combined liquid mixture;and combining the residual gaseous mixture containing said flavor andodor constituents with the de-oiled liquid mixture.

16. A method as stated in claim 15 wherein said oil removal stepincludes cooling the oily aqueous liquid mixture, centrifuging saidmixture; removing the aqueous portion of said mixture; filtering saidaqueous portion and heating said aqueous portion prior to combining withthe residual gaseous mixture with its flavor and odor constituents.

(References on following page) References Cited by the Examiner UNITEDSTATES PATENTS Hoyte 202-161 Milleville 99-205 5 Milleville 99-205 Cross99-205 X Dykstra 99-205 Lemmonier 99-71 1 4 2,680,708 6/ 1954 Cook202-186 2,729,564 1/ 1956 Keller 99-205 X OTHER REFERENCES Morgan etal.: Food Technology, 1953, vol. 7, No. 8, pp. 332-336.

A. LOUIS MONACELL, Primary Examiner.

ABRAHAM H. WINKELSTEIN, Examiner.

1. IN A METHOD OF SEPARATING AND ISOLATIN ODOR AND FLAVOR CONSTITUENTSOF NATURAL FRUIT AND BERRIES FROM WATER VAPOR AND NON-CONDENSABLE GASESCONTAINING A MINUTE QUANTITY OF SAID CONSTITUENTS THE STEPS OF:SEPARATING A SORUCE MATERIAL COMPOSED OF WATER VAPOR AND NON-CONDENSABLEGASES CONTAINING A MINUTE QUANTITY OF VOLATILE ODOR AND FLAVORCONSTITUENTS AT A TEMPERATURE BELOW ABOUT 43*C. AND ABSOLUTE PRESSURE OFNTO OVER 115 MM. HG IN A CONDENSATION ZONE TO CONDENSE NOT LESS THAN 70%BY WEIGHT OF THE WATER CONTAINED IN SAID SOURCE MATERIAL THEREBYINCREASING THE PARTIAL PRESSURE OF THE ODOR AND FLAVOR CONSTITUENTS INRESIDUAL VAPORS AND GASES; SEPARATING THE CONDENSED WATER FROM THERESIDUAL VAPORS AND GASES; PASSING SAID RESIDUAL VAPORS AND GASESTHROUGH A SERIES OF CONDENSATION ZONES MAINTAINED AT VIRTUALLY EQUALABSOLUTE PRESSURE BELOW ABOUT 115 MM. HG, THE TEMPERATURES IN SAID ZONESBEING MAINTAINED AT PROGRESSIVELY LOWER LEVELS BETWEEN ABOUT 22*C. AND2*C.; AND COMBINING THE CONDENSATES FROM SAID SERIES OF CONDENSATIONZONES TO OBTAIN A VIRTUALLY COLORLESS LIQUID CONTAINING SAID ODOR ANDFLAVOR CONSTITUENTS.